Capacitors, magnetic or inductive components such as inductors and transformers, and semiconductor devices are typically employed in electronic circuits, systems, and devices such as switching power supplies, switching voltage regulators, isolated power converters, power factor correction converters, filters in linear voltage regulators, analog integrated circuits (ICs), radio frequency (RF) transmitters, micro-electro-mechanical systems (MEMS), sensors, etc. The capacitors and magnetic/inductive components are typically incorporated into such electronic circuits, systems, and devices as discrete components. The discrete capacitors and magnetic/inductive components and the semiconductor devices can be interconnected on printed circuit boards (PCBs) or packaged onto substrate carriers, which can be implemented using metal lead frames or circuits on isolated base plates or substrates.
The use of discrete capacitors and magnetic/inductive components in such electronic circuits, systems, and devices has several drawbacks, however. For example, the discrete capacitors and magnetic/inductive components can occupy large areas on a PCB or substrate carrier. The discrete capacitors and magnetic/inductive components can also be high in profile, and therefore may not be well suited for use in low profile electronic devices such as wearable electronic devices, tablet computers, smartphones, notebook computers, and portable medical devices.
The interconnections between the discrete capacitors and magnetic/inductive components and the semiconductor devices can also occupy large areas on the PCB or substrate carrier. Parasitic inductance and capacitance distributed throughout the interconnections can also prevent electronic circuits, systems, and devices from functioning properly in high frequency (e.g., from megahertz (MHz) to gigahertz (GHz)) applications. The discrete capacitors can also have mechanical outline connections or terminals that introduce parasitic inductance while operating in the radio frequency (e.g., MHz) range. As a result, the effective capacitance of the discrete capacitors can be reduced and the impedance increased as the operating frequency rises above about a few hundred MHz.
In addition, wire-wound types of discrete inductive components often generate acoustic noise that can be sensed by human ears as the operating frequency dynamically changes within the range of several hertz to 20 kilohertz (KHz). Wire-wound magnetic components, such as inductors, coupled inductors, and transformers, also generally have large air spaces or gaps between coil turns, as well as between the coil windings and a magnetic core, which require large areas on the PCB or substrate carrier. The structure of such wire-wound magnetic components can also exhibit mechanical vibrations and generate acoustic noise that can be sensed by human ears.
Moreover, because it is generally difficult to test discrete capacitors and magnetic/inductive components and trim them properly when incorporated with semiconductor devices into such electronic circuits, systems, and devices, the discrete capacitors, discrete magnetic/inductive components, and semiconductor devices are typically tested separately. As a result, it can be difficult if not impossible to optimize such electronic circuits, systems, and devices due to variations in the tolerance and/or accuracy of the discrete capacitors and magnetic/inductive components incorporated therein.
FIG. 1 depicts a conventional voltage regulator and voltage delivery circuit 100 formed using discrete capacitors and magnetic/inductive components, and a semiconductor device. As shown in FIG. 1, the voltage regulator and voltage delivery circuit 100 includes a switching voltage regulator chip 102, a discrete inductor L0 and capacitor C0 forming a first LC filter (the “L0C0 filter”), a discrete inductor L1 and capacitor C1 forming a second LC filter (the “L1C1 filter”), and a discrete inductor L2 and capacitor C2 forming a third LC filter (the “L2C2 filter”). The L0C0 filter is connected between the switching voltage regulator chip 102 and each of the L1C1 filter and the L2C2 filter. The L1C1 filter is connected to a load 1, and the L2C2 filter is connected to a load 2. The load 1 and load 2 represent devices that require a supply voltage with low voltage ripple and low voltage noise. The L0C0 filter and the L1C1 filter form a 2-stage LC filter that attenuates the voltage ripple to a required level for the load 1. Similarly, the L0C0 filter and the L2C2 filter form another 2-stage LC filter that attenuates the voltage ripple to the required level for the load 2.
However, the conventional voltage regulator and voltage delivery circuit 100 has drawbacks in that it requires three (3) discrete capacitors (C0, C1, C2) and three (3) discrete inductors (L0, L1, L2), in addition to the switching voltage regulator chip 102. The first stage L0C0 filter effectively chokes the pulse width modulation (PWM) voltage provided by the switching voltage regulator chip 102 to obtain a DC voltage, normally with a peak-to-peak voltage ripple of about 1 to 30 millivolts (mV). Because such voltage ripple in the mV range is generally too high for any precision circuits that might be included in the loads 1 and 2, the second stage L1C1 and L2C2 filters are employed to further attenuate the voltage ripples down to several microvolts (μV). The inductors L1, L2 in the second stage LC filters are typically ferrite beat or RF magnetic inductors to provide impedance in the high frequency range. If a separate channel output for the load 2 is desired, then another discrete inductor and capacitor forming a fourth LC filter would be required, further increasing the area necessary to implement the conventional voltage regulator and voltage delivery circuit 100.